Progress Report December 2012

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Optimal design of a CO

₂

absorption unit

and assessment of solvent degradation

Progress Review Presentation

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Table of Content

1. Study of MEA degradation 2. Degradation modeling

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1. MEA degradation Influence of :

• Agitation rate • Temperature

• Gas composition

• Metals and inhibitors • Thermal degradation

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1. MEA semi-batch degradation

Experi

ment Start End

Time

Test

Agitation T Ptot PO2 PCO2 PN2 Gas flow

Mass

balance Solvent

Additives Problems Days rpm [°C] [bar] [bar] [bar] [bar] [mln/mi

n] [%] [wt% MEA] 17 31/07/12 7/08/12 7 Base case at 600 rpm 600 120 4 5 15 80 160 -1.33% 29.97 - Crystal formation in the condenser 18 10/08/12 17/08/12 7 O2 at 600 rpm 600 120 4 5 0 95 160 2.37% 29.99 - -

19 21/08/12 28/08/12 7 Temperature 600 140 4 5 15 80 160 -4.82% 29.99 - Crystal formation in the condenser 20 30/08/12 6/09/12 7 Temperature 600 55 4 5 15 80 160 2.17% 29.99 - - 21 11/09/12 18/09/12 7 Influence of SS metals 600 120 4 5 15 80 160 -37.59% 29.98 Fe2+, Cr3+, Ni2+, Mn2+ Mass losses, crystal formation 22 19/09/12 26/09/12 7 Influence of SS metals 600 120 4 5 15 80 160 -1.07% 29.99 Fe2+, Cr3+, Ni2+, Mn2+ Crystal formation in the condenser 23 27/09/12 4/10/12 7 Influence of Inh. A + SS 600 120 4 5 15 80 160 -1.70% 30% (MEA from UT Austin) SS metals + inh. A Bad dissolution of metals 24 5/10/12 12/10/12 7 Influence of DMTD + SS 600 120 4 5 15 80 160 -1.17% 29.99 SS metals + DMTD Bad dissolution of metals and inhibitor, power shortage (14h) 25 24/10/12 31/10/12 7 Infl. of Inh.a + HEDP + SS 600 120 4 5 15 80 160 -2.50% 30% (MEA from UT Austin) SS metals + inh.A + HEDP -

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1. MEA semi-batch degradation

Experi

ment Start End

Time Test Agitation T Ptot PO2 PCO 2 PN2 Gas flow Mass balance Solvent Additives Problems Days rpm [°C] [bar] [bar] [bar] [bar] [mln/m

in] [%] [wt% MEA] 26 1/11/12 8/11/12 7 Influence of HEDP + SS 600 120 4 5 15 80 160 -1.53% 29.99 SS metals + HEDP Crystal formation in the condenser 27 9/11/12 16/11/12 7 Influence of CO2 600 120 4 0 15 85 160 -3.83% 30.00 - Power shortage (4h) 28 19/11/12 26/11/12 7 Influence of O2 600 120 4 10 15 75 160 -1.50% 30.00 - Crystal formation in the condenser 29 27/12/12 4/12/12 7 Influence of CO2 600 120 4 5 30 65 160 -18.00% 30.02 - Mass losses, crystal formation 30 5/12/12 12/12/12 7 Influence of Temp 600 100 4 5 15 80 160 -6.87% 30.00 - Light Mass losses 31 13/12/12 20/12/12 7 Influence of CO2 600 120 4 5 30 65 160 0.00% -

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1.1 Agitation rate

• Linear dependence of the MEA loss on the agitation rate R² = 0.9965 R² = 0.9987 0 10 20 30 40 50 60 70 80 90 100 200 400 600 800 1000 1200 1400 1600 M E A los s (w t-%) Base Case O2

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Further observations:

• More HEI when rpm rises

• Less HEPO when rpm rises (also less when under O₂

only)

=> HEI is formed when O₂ diffusion is not limited

=> HEPO is formed when O₂ is less available

Base case P10 P15 P17 P11 Agitation rate 400 400 600 1380 MEA 22.17% 22.67% 20.09% 2.03% OZD 0.0451% 0.0500% 0.0480% 0.1240% HEI (Secondary axis) 0.1261% 0.0202% 0.1489% 3.9100% HEPO 0.2555% 0.2757% 0.2555% 0.0697% O2 P16 P18 P13 Agitation rate 400 600 1000 MEA 19.48% 12.64% 1.82% OZD 0.0058% 0.0145% 0.1724% HEI 0.0834% 0.4491% 3.2003% HEPO 0.0558% 0.0868% 0.0918%

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GC Comparison with pilot results => Experiment 17 has been chosen as base case

- 600rpm - 120°C - 4 bar - 5%O₂, 15%CO₂, 80%N₂ - 160 mln/min - 1 week -14000 -9000 -4000 1000 6000 11000 0 5 10 15 20 25 30 35 40 45 S ign al G C -F ID ( mV)

Temps de rétention (min)

Base Case Pilot

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1.2 Temperature

• Higher temperature leads to higher MEA losses

• Experiment at 100°C gives unexpected results, maybe due to mass losses

0 5 10 15 20 25 30 35 40 20 40 60 80 100 120 140 160 M E A los s (w t-%) Temperature (°C)

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1.2 Temperature P20 P30 P17 P19 Temperature 55 100 120 140 MEA 23.66% 27.60% 20.09% 19.08% OZD 0.0097% 0.0230% 0.0480% 0.0314% HEI 0.0099% 0.3838% 0.1489% 0.0359% HEPO 0.0315% 0.0507% 0.2555% 1.0057%

• HEPO is formed at higher temperature, confirms a mechanism of cyclization

• HEI is less formed at higher temperature, maybe due to less Oxygen present in the liquid

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1.2 Temperature • NH₃ emissions -50 0 50 100 150 200 250 300 0:00:00 24:00:00 48:00:00 72:00:00 96:00:00 120:00:00 144:00:00 168:00:00 192:00:00 NH 3 (ppm) Time (h) 55°C 100°C 120°C 140°C

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1.3 Gas composition: O₂

• The more oxygen, the more degradation • More oxygen => more HEI and less HEPO

• In the absence of O₂, no degradation at 120°C

0 10 20 30 40 50 60 0 2 4 6 8 10 12 M E A los s (w t-%) O₂ content (vol-%) P27 P17 P28 Vol-% Oxygen 0 5 10 MEA 38.60% 20.09% 20.11% OZD 0.0577% 0.0480% 0.0328% HEI 0.0000% 0.1489% 0.3386% HEPO 0.0000% 0.2555% 0.1002%

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1.3 Gas composition: O₂ • NH₃ emissions -50 0 50 100 150 200 250 300 350 400 450 0:00:00 24:00:00 48:00:00 72:00:00 96:00:00 120:00:00 144:00:00 168:00:00 192:00:00 NH 3 (ppm) Time (h) 0% O2 5% O2

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1.3 Gas composition: CO₂

• The more CO₂, the less degradation

• Under-estimated effect • 3rd_{point to be confirmed} 0 5 10 15 20 25 30 35 40 45 0 10 20 30 40 M E A los s (w t-%) CO₂ content (vol-%) P18 P17 P29-P31 vol-% CO2 0 15 30 MEA 12.64% 20.09% 22.31% OZD 0.0145% 0.0480% 0.0942% HEI 0.4491% 0.1489% 0.3006% HEPO 0.0868% 0.2555% 0.0000%

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1.3 Gas composition: CO₂ • NH₃ emissions -100 0 100 200 300 400 500 600 700 800 0:00:00 24:00:00 48:00:00 72:00:00 96:00:00 120:00:00 144:00:00 168:00:00 192:00:00 NH 3 (ppm) Time (h) 0% CO2 15% CO2 30% CO2

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1.4 Metals

• Metals catalyze degradation:

• Mn7+_{> Fe}2+_/Cu2+ ≥ Cu2+_>

Cr3+_/Ni2+_{> Fe}2+_{> Fe}3+_{> Cr}3+

> V5+ _{>> Ti, Co, Mo, Ni, Sn,}

Se, Ce, Zn

• 49% MEA loss instead of 32.5%!

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1.4 Metals and inhibitors

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• Inh. A, DMTD, HEDP, Inh.A/HEDP

0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00

SS SS + Inh. A SS + DMTD SS+ Inh.A/HEDP SS + HEDP

M E A los s ( wt -%)

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P22 P23 P24 P25 P26

Additives SS SS + Inh. A SS + DMTD SS+ Inh.A/HEDP SS + HEDP

MEA 14.44% 27.43% 26.72% 23.98% 14.96%

OZD 0.0546% 0.0393% 0.1253% 0.0439% 0.0442%

HEI 0.4095% 0.0000% 0.0000% 0.0000% 0.5027%

HEPO 0.2544% 0.1987% 0.0648% 0.1815% 0.2309%

• Good inhibition of HEI formation with Inh. A, DMTD, Inh.A/HEDP, but not with HEDP alone

• HEPO formation is only inhibited by DMTD, but inthis case, more OZD

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1.4 Additives

• NH₃ emissions: influence of metals?

-100 100 300 500 700 900 1100 0 1 2 3 4 5 6 7 N H3 co nc en tr at io ns (p pm ) P17, BC, 120°C P22, BC + metals mix, 120°C

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1.4 Additives • NH₃ emissions -50 0 50 100 150 200 250 300 350 400 450 0:00:00 24:00:00 48:00:00 72:00:00 96:00:00 120:00:00 144:00:00 168:00:00 192:00:00 NH 3 (ppm) Time (h) BC metals BC + metals + inh.A BC + metals + DMTD

BC + metals + Inh.A + HEDP

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1.5 Thermal degradation

• Objective is to test the stability of degradation inhibitors at high temperatures

• Stainless steel cylinders filled with amine solvents and set in an oven at 120 - 140°C

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• Objective is to test the stability of degradation inhibitors at high temperatures

• Tests at 120 and 140°C in stainless steel cylinders

P1 - 120°C Start: 29/08/2012 P2 - 140°C Start: 28/09/2012

Θ1 MEA 30% + CO2 Θ1 MEA 30% + CO2

Θ2 MEA 30% + CO2 + inh.A Θ2 MEA 30% + CO2 + inh.A

Θ3 MEA from pilot + CO2 Θ3 MEA from pilot + CO2

Θ4 MEA from pilot + CO2 + inh. A Θ4 MEA from pilot + CO2 + inh. A

P3 - 140°C Start: 09/11/2012 P4 - 140°C Start: 14/12/2012

Θ1 MEA + CO2 + metal mix Θ1 MEA

Θ2 MEA + CO2 + HEDP Θ2 MEA + metal mix

Θ3 MEA + CO2 + DMTD Θ3 MEA + CO2 + TDE

Θ4 MEA + CO2 + metal mix + HEDP Θ4 MEA + CO2 + DTPA

Θ5 MEA + CO2 + DTDP

Θ6 MEA + CO2 + inh. A + HEDP

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• Inh. A has few effect on thermal degradation • DMTD is not stable at 140°C

• Thermal degradation is not catalyzed by metals

MEA loss (wt-%) 120°C 140°C

MEA/CO2 11.58 40.70

MEA/CO2 + inh.A 7.88 38.54 Degraded MEA/CO2 8.49 30.58 Degraded MEA/CO2 + inh.A 6.44 28.27

MEA/CO2 + SS 40.56

MEA/CO2 + HEDP 41.63

MEA/CO2 + DMTD 54.00

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• No HEPO nor HEI in thermal degraded sample (120 – 140°C)

• But other products: HEIA and HEEDA ? Not quantified…

-60000 -40000 -20000 0 20000 40000 60000 80000 100000 0 10 20 30 40 50 GC sig n al (mV) P3Θ2, MEA + CO₂ + HEDP 1 week 3 weeks

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1. MEA degradation • Nitrogen balance: P17 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 T0 Tf NH3 BHEOX HEPO HEI OZD MEA

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1. MEA degradation • Nitrogen balance: P22 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 T0 Tf NH3 BHEOX HEPO HEI OZD MEA

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2. Degradation modeling • 2 types de dégradation :

– Dégradation oxydative

– Dégradation thermique

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4) Dégradation : réaction et cinétique Travail de Ségolène • Equation : • Vitesse : Avec => k, E_a et ordre de O₂ => Ordre de CO₂ et de MEA

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Comparaison de vitesses de réaction (1) 0 500 1000 1500 2000 2500 3000 3500 4000 4500 Dégradation normale Dégradation accélérée X10 Quantité de MEA dégr a dé (kg/moi s)

Dégradation en fonction de l’appareil et de la vitesse de dégradation

Stripper Absorber

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Comparaison de vitesses de réaction (2) 1250 1255 1260 1265 1270 1275 1280 1285 1290 Chaleur au stripper (kW) 0 0.2 0.4 0.6 0.8 1 1.2 1.4 x 1 x 10

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Profil de O2 vapeur dans l'absorber 3.675E-03 3.680E-03 3.685E-03 3.690E-03 3.695E-03 3.700E-03 3.705E-03 3.710E-03 3.715E-03 3.720E-03 0 2 4 6 8 10 12 14 16 18 20 Débit de O 2 (kg /s) Etages ss dégradation dégradation x1 dégradation x10

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Profil de O2 liquide dans l'absorber 0.00E+00 2.00E-07 4.00E-07 6.00E-07 8.00E-07 1.00E-06 1.20E-06 1.40E-06 1.60E-06 1.80E-06 2.00E-06 0 2 4 6 8 10 12 14 16 18 20 Débit de O 2 (kg /s) Etages ss dégradation dégradation x1 dégradation x10

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Influence de la pression au stripper (1)

Pression stripper (bar) Zone T pied (°C) T tête (°C)

1,5 absorber 51,3 64,1 stripper 112,3 96,2 1,7 (normal) absorber 51,2 64,0 stripper 115,8 98,9 2 absorber 51,3 64,1 stripper 120,2 102,6 2,5 absorber 52,2 64,3 stripper 126,4 107,7 0 200 400 600 800 1000 1200 1400 1600 1.5 1.7 2 2.5 MEA dégra dé (kg/moi s)

Pression au stripper (bars)

MEA dégradée en fonction de l’appareil et de la pression au stripper

Stripper Absorber

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Influence de la pression au stripper (2) 0 200 400 600 800 1000 1200 1400 1.5 1.7 2 2.5

Pression au stripper (bars)

Chaleur au stripper (kW) 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 1.5 1.7 2 2.5 Acide formique (% mass)

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20th_{december 2012}

Perspectives

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3. Perspectives

• January 2013 : last experiments

– Repetition of failed experiment – O2 and CO2

– Limit: FTIR availability

• February 2013 : Model building and exploitation • March 2013 : Beginning of the redaction

• Mai 2013 : End of the redaction • June-July 2013 : Public defense

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20th_{december 2012}